It doesn't look like Athletic Bilbao has complained about the situation.
The source is Fabrizio Romano again so this very awkward...He is still keen on completing the deal. Barcelona is only needed to pay for Nico's release clause and that's it. They just don't want any installments like I said before.
I hope Barcelona finishes it without making a regulation breach.
It seems that Williams wants guarantees from Barcelona so as not to end up in a situation like Olmo, who they could not register for the entire season. I would say that this is an adequate condition. The problem is that Barcelona cannot give these guarantees since it does not depend only on them, in general, it is a confusing situation. I haven't been following Barcelona's financial problems for a long time, but as I understand it, they are still serious and are constantly balancing on the edge when making up the budget.